曲线斜拉桥π形梁剪力滞效应分析及模型试验研究

Shear Lag Effect Analysis and Model Test of π-shaped Girder of Curved Cable-stayed Bridge

以刚果已建成的一座混凝土曲线斜拉桥为实例,通过ANSYS建立全桥有限元模型,研究在施工过程中及成桥状态下π形主梁顶板的正应力分布及剪力滞效应的变化情况。同时,通过全桥模型试验验证曲线斜拉桥在施工过程中剪力滞效应的变化规律。结果表明:π形主梁的曲线内侧和外侧的剪力滞系数差别较大,甚至出现内侧边肋为正剪力滞效应、外侧边肋为负剪力滞效应的情况;随着施工的进行,各个截面的剪力滞效应越来越明显。

Taking a concrete curved cable-stayed bridge built in Congo as an example,a finite element model of whole bridge was established by ANSYS.The variation of the normal stress distribution and shear lag effect of theπ-shaped main girder roof under the construction process and the condition of completed bridge were studied in this paper.M eanwhile,the variation law of shear lag effect during the construction process of the curved cable-stayed bridge was validated by model test.The results show that the shear lag coefficients on medial and lateral sides ofπ-shaped main girder of the curved cable-stayed bridge are quite different,even the shear lag coefficient on medial rib is positive while that on lateral rib is negative T he shear lag effect in each section gets more obvious with the construction procedur.